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Updated: Jul 8, 2026
06:38
High Sensitivity Measurement of Transcription Factor-DNA Binding Affinities by Competitive Titration Using Fluorescence Microscopy
Published on: February 7, 2019
PDZ domain-mediated dimerization and homeodomain-directed specificity are required for high-affinity DNA binding by
Prabhat Kumar Purbey1, Sunita Singh, P Pavan Kumar
1National Centre for Cell Science, Ganeshkhind, Pune 411007, India.
Nucleic Acids Research
|January 12, 2008
Summary
SATB1, a key transcription factor, binds DNA via a specific palindromic sequence. This binding, dependent on dimerization, represses transcription, offering insights into gene regulation.
Area of Science:
- Molecular Biology
- Genetics
- Epigenetics
Background:
- SATB1 is a crucial chromatin organizer and transcription factor in T-cells.
- Understanding SATB1's DNA binding is vital for deciphering its role in gene regulation.
Purpose of the Study:
- To determine the optimal DNA-binding sequence for SATB1.
- To elucidate the mechanism of SATB1-DNA interaction and its impact on transcription.
Main Methods:
- Random oligonucleotide selection to identify the consensus SATB1-binding sequence (CSBS).
- Biochemical binding assays using modified SATB1 and DNA targets.
- In vivo reporter assays to assess transcriptional activity.
Main Results:
- The CSBS is a palindrome with AT-rich half-sites, similar to homeodomain-binding elements.
- SATB1 binding is dimerization-dependent, with homeodomains binding antiparallel via the minor groove.
- SATB1 binding to CSBS generally represses transcription, proportional to binding affinity.
Conclusions:
- SATB1 recognizes a specific palindromic DNA sequence through dimerization-dependent homeodomain binding.
- This interaction leads to transcriptional repression, providing mechanistic insights into SATB1's regulatory function.
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